CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating Activities:
Net income	$ 499,146	$ 364,865
Adjustments to reconcile net income to net cash provided by operating activities
Provision for credit losses	71,482	30,943
Depreciation, amortization and accretion, net	62,591	64,726
Stock-based compensation expense	24,532	23,852
Amortization of premium on securities, net	1,201	2,048
Accretion of discount and deferred fees on loans, net	(13,105)	(17,237)
Mortgage servicing rights fair value changes, net of economic hedge	13,065	(41,087)
Non-designated derivatives fair value changes, net	(271)	957
Originations and purchases of mortgage loans held-for-sale	(1,532,325)	(2,377,249)
Early buy-out exercises of mortgage loans held-for-sale guaranteed by U.S. government agencies, net of subsequent paydowns or payoffs	9,323	69,605
Proceeds from sales of mortgage loans held-for-sale	1,500,870	2,664,774
Bank owned life insurance (“BOLI”) (gains) losses	(2,849)	588
(Increase) decrease in trading securities, net	(536)	882
Decrease in brokerage customer receivables, net	2,345	5,741
Gains on mortgage loans sold	(27,777)	(37,022)
Gains on premium financing receivables sold	(890)	0
Losses on investment securities, net	959	13,682
(Gains) losses on sales of premises and equipment, net	1,547	2,114
Losses (gains) on sales and fair value adjustments of other real estate owned, net	121	(805)
(Increase) decrease in accrued interest receivable and other assets, net	(269,677)	22,542
Increase in accrued interest payable and other liabilities, net	156,697	261,253
Net Cash Provided by Operating Activities	496,449	1,055,172
Investing Activities:
Proceeds from payments, maturities and calls of available-for-sale securities	2,107,201	275,336
Proceeds from payments, maturities and calls of held-to-maturity securities	138,154	174,211
Proceeds from sales of equity securities with readily determinable fair value	23,592	21,753
Proceeds from sales and capital distributions of equity securities without readily determinable fair value	67	1,232
Purchases of available-for-sale securities	(1,731,266)	(1,438,270)
Purchases of held-to-maturity securities	(407,527)	(623,011)
Purchases of equity securities with readily determinable fair value	(45,954)	(54,495)
Purchases of equity securities without readily determinable fair value	(9,350)	(9,892)
Redemptions (purchases) of Federal Home Loan Bank and Federal Reserve Bank stock, net	20,719	(42,778)
Distributions from investments in partnerships, net	5,540	3,506
Net cash paid in business combinations	(5,147)	0
Proceeds from sales of premium financing receivables, net	405,560	0
Proceeds from sales of other real estate owned	1,635	3,802
Decrease in securities purchased under resale agreements with terms exceeding three months, net	0	700,000
(Increase) decrease in interest-bearing deposits with banks, net	(458,115)	1,400,793
Increase in loans, net	(2,644,535)	(3,324,304)
Redemption of BOLI	553	960
Purchases of premises and equipment, net	(29,218)	(37,462)
Net Cash Used for Investing Activities	(2,628,091)	(2,948,619)
Financing Activities:
Increase in deposit accounts, net	2,090,137	701,597
Increase (decrease) in other borrowings, net	48,016	(18,103)
Increase in Federal Home Loan Bank advances, net	10,000	1,075,000
Proceeds from common stock offering, net	0	285,721
Cash payments to settle contingent consideration liabilities recognized in business combinations	(57)	0
Issuance of common shares resulting from the exercise of stock options and employee stock purchase plan	6,667	8,230
Common stock repurchases for tax withholdings related to stock-based compensation	(1,662)	0
Dividends paid	(94,277)	(80,556)
Net Cash Provided by Financing Activities	2,058,824	1,971,889
Net (Decrease) Increase in Cash and Cash Equivalents	(72,818)	78,442
Cash and Cash Equivalents at Beginning of Period	490,966	411,205
Cash and Cash Equivalents at End of Period	$ 418,148	$ 489,647